The present invention relates generally to ground working equipment and vehicles used in construction, and more particularly to earth compacting apparatus and other tools attached to such vehicles for performing various ground working tasks, such as compacting loose fill dirt in trenches on construction sites, or in road construction or repair.
When constructing buildings, roads, and other developments, it is necessary to dig trenches for underground pipelines and the like. When the dirt is refilled, the dirt must be closely packed to prevent or reduce the risk of later settling and possible damage as a result of foundation cracking. It is also necessary to compact dirt during road repair or construction, since substantial damage may result from settling earth under roadways. The asphalt surface of roads must also be compacted or smoothed by suitable rollers.
One technique used in the past for compacting earth in trenches has been first to push fill dirt into the trench using a tractor with a blade, subsequently compacting the earth with vibratory devices. This is a slow and labor-intensive process. Compaction wheels are known which can be mounted on a tractor or other earth working vehicle which is then driven over the ground to be compacted. In U.S. Pat. No. 4,023,288 of Roe, for example, a compaction roller is attached to a backhoe or similar boom device mounted on a tractor. An integral scraper blade is provided for scraping fill dirt into a trench for subsequent compaction. This allows a trench to be compacted much faster than with vibratory devices, since a single vehicle is used both to fill in and to compact the dirt. The compaction roller is in the form of a cylindrical drum with teeth projecting radially outwardly from its surface.
U.S. Pat. No. 4,269,535 of Schultz shows a bulldozer having a blade at its forward end and an earth compactor at its rear end. The earth compactor comprises three sets of rotatably mounted sheep's foot compaction wheels on a common axle which can be raised and lowered by an hydraulic actuator to place the wheels in contact with the ground surface and to apply down pressure on the wheels.
In both of these devices, the compaction width of the assembly is fixed so that more than one pass of the vehicle may be necessary for some trench widths.